1. Field of the Invention
This invention relates to optics and in particular, to an improved additive lamphouse for contact printing.
2. Description of the Prior Art
In a contact printer, the to-be-exposed material (hereinafter referred to as the contact) is exposed in contact with a negative and the light passes through the back of the negative to the coated side of the contact. The emulsion side of the negative is placed facing the emulsion side of the contact and the two are placed in contact at all points. The various parameters of the incident light will therefore affect the print produced as a contact print. It is therefore important to be able to control the incident light on the negative if one wishes to be able to produce the desired print.
The light used as a source for contact printers may be produced in an additive lamphouse. These devices emit a light and provide certain controls over the light prior to the exposure of the negative and the positive or negative contact. However, the controls which one can exercise over this light source have been limited as explained hereinafter and the contacts produced therefore have suffered from certain drawbacks and disadvantages.
In the past, additive lamphouses have had certain limitations with respect to their structure and their ability to reproduce quality images. Additive colour lamphouses are used to illuminate the negative and the contact during the exposure thereof in the contact printing process wherein the colour of the incident light on the negative is particularly important.
An example of a situation in which the colour of the incident light is very important is as follows. During the filming of a movie, it has been found that it may take a considerable length of time to film a sequence of events which ultimately may involve a very short period of time in the final product. If the shooting of a particular scene occurs over a period of time in which various lighting conditions occur, such as during the afternoon hours when the daylight becomes redder with time, and that scene is intended to occur over a much shortened period of time in the final movie, it is desired to stabilize the colour of the print produced to properly represent a short period of time. Thus, the colour in the final print may remain constant to provide the viewer with the proper perspective of time lapse.
These particular changes in the colour of the images on the original film must be stabilized by the changes in the colour of the illumination when the film or the print (contact) is produced as a final product.
One of the particular advantages of the lamphouse of the present application is its ability to adjust and control the colour of the contact produced. Compensations can be made during the process to produce constant lighting conditions in the printing stage to reflect the desired results.
The present invention will be disclosed for use in association with a contact printer but is adaptable for use in any device wherein an additive lamphouse may be used.